This invention relates generally to a process of recovering copper from ores containing copper as oxides, and more particularly, the invention relates to a process for recovering copper from ores containing atacamite/paratacamite utilizing a special promoter collector for the copper.
Copper minerals in the oxidized zone of porphyry copper deposits are categorized broadly as copper "oxides". These oxides include atacamite/paratacamite [Cu.sub.2 (OH).sub.3 Cl], azurite/malachite [CU.sub.3 (CO.sub.3).sub.2 (OH).sub.2 /Cu.sub.2 (CO.sub.3)(OH.sub.2 ], chrysocolla [CuSiO.sub.3.nH.sub.2 O], cuprite [CU.sub.2 O], etc. The copper minerals in the underlying sulfide rich and primary sulfide zones include chalcocite [Cu.sub.2 S], chalcopyrite [CuFeS.sub.2], and bornite [CU.sub.5 FeS.sub.4].
One commonly used method for concentrating copper sulfide minerals utilizes a froth flotation circuit utilizing known sulfide collectors. However, the normally used collectors for sulfide minerals generally will not react upon the "oxide" copper minerals, and, hence, the recovery of copper from the copper oxide minerals often requires treatment steps which are different from those used with the sulfide ores. The recovery of chrysocolla and iron oxide minerals from their ores by flotation utilizing hydroxamic acids and salts such as potassium octylhydroxamate as chelating agents for the copper is described in U.S. Pat. No. 3,488,494.